The fungal dimension of biodiversity: magnitude, significance, and conservation

Isopestacin, an isobenzofuranone from Pestalotiopsis microspora, possessing antifungal and antioxidant activities

The genus Pestalotiopsis has received considerable attention in recent years, not only because of its role as a plant pathogen but also as a commonly isolated endophyte which has been shown to produce a wide range of chemically novel diverse metabolites. Classification in the genus has been previously based on morphology, with conidial characters being considered as important in distinguishing species and closely related genera. In this review, Pestalotia, Pestalotiopsis and some related genera are evaluated; it is concluded that the large number of described species has resulted from introductions based on host association. We suspect that many of these are probably not good biological species. Recent molecular data have shown that conidial characters can be used to distinguish taxa; however, host association and geographical location is less informative. The taxonomy of the genera complex remains confused. There are only a few type cultures and, therefore, it is impossible to use gene sequences in GenBank to clarify species names reliably. It has not even been established whether Pestalotia and Pestalotiopsis are distinct genera, as no isolates of the type species of Pestalotia have been sequenced, and they are morphologically somewhat similar. When selected GenBank ITS accessions of Pestalotiopsis clavispora, P. disseminata, P. microspora, P. neglecta, P. photiniae, P. theae, P. virgatula and P. vismiae are aligned, most species cluster throughout any phylogram generated. Since there appears to be no living type strain for any of these species, it is unwise to use GenBank sequences to represent any of these names. Type cultures and sequences are available for the recently described species P. hainanensis, P. jesteri, P. kunmingensis and P. pallidotheae. It is clear that the important species in Pestalotia and Pestalotiopsis need to be epitypified so that we can begin to understand the genus/genera. There are numerous reports in the literature that various species produce taxol, while others produce newly discovered compounds with medicinal potential and still others cause disease. The names assigned to these novel compound-producing taxa lack an accurate taxonomic basis, since the taxonomy of the genus is markedly confused. Until the important species have been epitypified with living strains that have been sequenced and deposited in public databases, researchers should refrain from providing the exact name of species.

http://www.im.ac.cn/UserFiles/File/2011/201109/Fungal%20Diversity-Sajeewa(1).pdf

Pestalotiopsis—morphology, phylogeny, biochemistry and diversity

Aim As a result of the extinctions of several large frugivorous birds (and one ﬂying fox)and the diminished ranges of others, Tonga now has a relatively small number ofeffective seed dispersers, especially for large-seeded plants. We estimate the bill widthand gape of the two largest known extinct pigeon species (Ducula) present in Tongaprior to human arrival. We then estimate which native rain forest species had fruits thatwould have probably been included in the diets of these extinct birds but which may notbe dispersed regularly by the smaller frugivores present today.Methods Bill width for the two largest extinct pigeons was derived by extrapolatingfrom the size of fossil bones and measurements of skeletons of extant Ducula species.Ducula and Ptilinopus species have distensible jaws, and therefore their gape allowsthem to swallow objects broader than their bill width. We estimated the gape width andmaximum ingestible fruit size that both the extinct and extant species could consume, byextrapolating from feeding observations of extant Ducula and Ptilinopus species (usingknown bill widths and fruit sizes). We determined whether those plant species whosefruit diameters exceed the mean gape width of the largest remaining avian frugivore inTonga (Ducula paciﬁca Gmelin) appeared adapted for dispersal by birds or ﬂying foxes.Results Approximately 79% of the native rain forest trees and lianas in Tonga producefruits whose morphology suggests that they are adapted to vertebrate dispersal. Billwidth estimates derived from the bones of the extinct Ducula sp. nova suggest that thispigeon could swallow fruit up to 48 mm in diameter, whilst the smaller Ducula cf. davidBalouet & Olson is estimated to have been able to swallow fruit up to 36 mm indiameter. Plant species whose fruits are too large to be swallowed by Tonga’s largestextant frugivorous bird (D. paciﬁca) yet display fruit characteristics suggesting birdswere likely to have been their predominant vertebrate disperser in pre-human timesinclude: Calophyllum inophyllum L., Cerbera odollam Gaertn, Planchonella garberiChristophersen, P. membranacea Lam., Pometia pinnata J. R. & G. Forst., Syzygiumquandrangulatum (A. Gray) Merr. & Perry, Syzygium richii (A. Gray) Merr. & Perryand Terminalia catappa L.Main conclusions There is now no avian disperser in Tonga for plant species whosefruits measure >28 mm in diameter (the maximum gape of D. paciﬁca). Althoughfrugivorous ﬂying foxes (Pteropus tonganus Quoy & Gaimard) may eat the fruit anddisperse the seeds of the eight plant species identiﬁed with large fruits, the frequency ofdispersal by birds was probably much higher in the past. Species that once relied on thelarge extinct pigeons for dispersal may have become reduced in abundance in theirabsence.KeywordsPlant–animal interactions, frugivore, rain forest, extinction, pigeon, Ducula, islands.

Potential disruptions to seed dispersal mutualisms in Tonga, Western Polynesia

Comparative studies have suggested that fruit traits, such as color, size, and protection, have evolved as covarying character complexes («dispersal syndromes») in response to selection by frugivorous dispersers. However, many comparative studies of disperser-specific syndromes have used species as sampling units, a method which implicitly assumes that character complexes evolve de novo in each species. This approach overestimates the number of times a character complex has evolved because covariation that results from common ancestry (plesiomorphy) is confounded with covariation across independent lineages (convergence)

A. H. M. Jayasuriya

Papers

Handbooks of the Flora Of Papua New Guinea